Plasma cutting on a Galvanised Grille

[Heavy Hand]

While walking round a boot sale looking for lumps of metal, I found a boot scraper steel grille 3'x2' for £10.

It seemed to me ideal as backing for plasma cutting being that it is made of vertical metal strips and ridgid enough to be supported on trestles. The only thing is that it is galvanised....

Being that I intend to cut outside and have purchased some of those 3M disposable welding masks, how risky is it as a backing when cutting thin sheet?.

 

[eSCHEn]

Depends on how decent the masks are really.

It's outside so good ventilation. The problem is when the ventilation wafts back at you or isn't good enough, then you're relying on the PPE.

How thin is thin? If it's really thin, like under a couple of mm then then power is going to be pretty low and so fumage will be limited anyway.

"Disposable" conjures images of those awful white things with the metal nose band that serve neither man nor beast.

Also - what's around you? Are they going to be dosed accidentally?

 

[Parm]

Anything galvanised will have a coating of Zinc, burning zinc which you will inevitably do with the plasma will produce zinc fume is likey to cause zinc fume fever which manifests as flu like symptoms to start off with and then worse

If you want to use the metal which does sound like it will be perfect for the job, I would throw it on to a large bonfire to allow the zinc to burn off then you should be good to go with minimum precautions

 

[Heavy Hand]

The mask should be pretty decent.... http://www.amazon.co.uk/3M-9928-Val...&redirect=true&ref_=oh_aui_detailpage_o02_s00.

But like the bonfire idea.....I have a neighbour with a field and a love of bonfires!

 

[Parm]

The mask should be pretty decent.... http://www.amazon.co.uk/3M-9928-Val...&redirect=true&ref_=oh_aui_detailpage_o02_s00.

But like the bonfire idea.....I have a neighbour with a field and a love of bonfires!

This masks seem quite expensive to me. Ditch the search for welding and try a search for a disposable P3 respirator, this is the highest level of dust and fume protection in a disposable respiratory, you should find some cheaper. The valve isn't important as you will only be using for short periods of hobby use. If your working outside then it may not even be necessary as the fume will disperse quickly

 

[Heavy Hand]

Guess I just went for 3m coz I trust their stuff and wanted to be sure that it would fit under a welding helmet....I'll Look harder when i've gone through the box.

I try to work outside or with good ventilation when ever possible.....seen some of those people with lung problems and being unable to breathe really seems to cramp your style...i take reasonable precautions and the rest is in the lap of the gods.

Always wanted to make a loose mask with pumped fresh air from outside the shed .....ie well away from the nuisance dust etc and not with all faff and filters of a compressor fed mask......not talking toxic vapour just blowing fresh air at your face rather than fumes.......Guess a bit like Darth Vaders breathing assist....under his welding helmet!

 

[Kent]

Use it for a boot scraper and make a plasma grill out of v point up rsa
Galv poisoning is horrid

 

[Ed.]

You could try spraying it with Hydrocloric acid to remove the zinc assuming you take the appropriate safety measures to protect yourself from the acid spray?

 

[Master-of-none]

You could try soaking it in sodium hydroxide solution to remove the zinc (take the appropriate safety measures to protect yourself). Sodium hydroxide won't dissolve the steel.
The reaction should release hydrogen gas, so something else to be aware of.

 

[Kent]

It's a 3ft x 2 ft section you paid a tenner for right? Chuck it in scrap or put it on the " might come in pile"
Some of the measures mentioned seem to forget that
Just make something up a new

 

[Heavy Hand]

Solved...

Big bonfire, big field, no people....no galvanising!.......also now a bit less flat,but ok.

I went for this method mainly as I recalled I have had no end of garden incinerators, all galvanised until the first bonfire!